In the manufacture of liquid crystal displays, it is necessary to transfer a glass substrate from a cassette to a production line, and execute a wanted manufacture process. Furthermore, in the transfer process, the glass substrate loaded in the cassette is picked from the cassette for a sampling inspection, and then is placed back to the cassette after it is qualified by the sampling inspection.
However, generally speaking, the glass substrate is usually 0.4-0.7 mm in thickness, and is fragile, so that the glass substrate is easily broken in the loading or unloading process thereof. If the placed position of the glass substrate on the cassette is incorrect, then the glass substrate is more easily broken when it is loaded/unloaded from the cassette. Referring now to FIGS. 1a to 1d, which show several incorrect placement situations of a glass substrate on a cassette, wherein FIG. 1a is a schematic view showing a glass substrate which is slanted to the left side; FIG. 1b is a schematic view showing a glass substrate which is slanted to the right side; FIG. 1c is a schematic view showing a glass substrate which is slanted to the outside; and FIG. 1d is a schematic view showing a glass substrate which is slanted and rotated. Additionally, some problems, such as shaking and unstable airflow, easily happen during the transfer process, which can cause the glass substrate to be dropped and broken. That is, in the traditional technology, since the placement precision of the glass substrate is low, the glass substrate is easily broken when it is picked/placed, and costs are increased.
As a result, it is necessary to provide a pick-and-place device for a glass substrate to solve the above-mentioned problems.